Im excluding lords, which only affect specific creatures, though Ive included a few anthems that allow you to select a specific creature type since those have broader applications than some like Lord of Atlantis
These consistently re-occurring play patterns illustrate how relevant Unholy Heat is in the current Modern format
That makes it a prime flicker target to strip the table of resources, which is the direction most Kefka decks take
There is no specific limit to how many planeswalkers are allowed on a deck
It costs only 4 mana, it can go into every deck that has a commander with a relevant trigger (which they often do), and if you build a typal strategy, this artifact creature can help you even further
Neither of the new commanders here made a long-term splash in the format, both under 600 decks on EDHrec (which is WEIRD to me), but I think the deck as a whole pushed towards better, long-terms changes